Thermal request mediating device

ABSTRACT

A thermal request mediating device includes a calculation unit configured to calculate amounts of heat for thermal circuits, a mediation unit configured to determine amounts of absorbed heat or amounts of discharged heat which are allocated to the thermal circuits based on amounts of heat transferable between the thermal circuits, and a distribution unit configured to distribute amounts of absorbed heat or amounts of discharged heat to units which are included in each thermal circuit based on the determined amounts of absorbed heat or amounts of discharged heat.

INCORPORATION BY REFERENCE

The disclosure of Japanese Patent Application No. 2019-053636 filed onMar. 20, 2019 including the specification, drawings and abstract isincorporated herein by reference in its entirety.

BACKGROUND 1. Technical Field

The disclosure relates to a thermal request mediating device.

2. Description of Related Art

Japanese Patent Publication No. 2015-186989 (JP 2015-186989 A) disclosesa vehicular air conditioner that includes a refrigeration circuit, a lowcoolant-temperature circuit, and a high coolant-temperature circuit,enables the refrigeration circuit and the high coolant-temperaturecircuit to exchange heat via a condenser, and enables the refrigerationcircuit and the low coolant-temperature circuit to exchange heat via arefrigerant-coolant heat exchanger. In the vehicular air conditionerdescribed in JP 2015-186989 A, improvement in efficiency of therefrigeration circuit can be achieved by providing a subcooling (SC)condenser that can exchange heat between the refrigeration circuit andthe low coolant-temperature circuit and promoting cooling of arefrigerant of the refrigeration circuit using the SC condenser.

SUMMARY

In a system in which heat can be transferred between a plurality ofthermal circuits as described in JP 2015-186989 A, there are manycombinations of heat absorption/discharge requests from units which areincluded in thermal circuits and mediation of the heatabsorption/discharge requests is complicated. Accordingly, there is roomfor improvement in a structure for mediating thermal requests from aplurality of units.

Therefore, the disclosure provides a thermal request mediating devicethat can efficiently mediate thermal requests from a plurality of unitsin a vehicle including the plurality of units performing absorption ordischarge of heat.

A thermal request mediating device according to an aspect of thedisclosure is mounted in a vehicle including a first thermal circuitconfigured to circulate a high-temperature coolant, a second thermalcircuit configured to circulate a low-temperature coolant, a thirdthermal circuit configured to circulate a refrigerant while changing astate of the refrigerant and to exchange heat with the first thermalcircuit and the second thermal circuit, and a plurality of unitsconfigured to perform absorption or discharge of heat via any one ofheat mediums which circulate in the first thermal circuit, the secondthermal circuit, and the third thermal circuit. The thermal requestmediating device comprising: an acquisition unit configured to acquireamounts of heat which are requested by the plurality of units, theamounts of heat being amounts of absorbed heat or amounts of dischargedheat; a calculation unit configured to calculate amounts of heat whichare requested by the first thermal circuit, the second thermal circuit,and the third thermal circuit based on the amounts of heat which arerequested by the plurality of units and which are acquired by theacquisition unit; a mediation unit configured to determine amounts ofheat which are allocated to the first thermal circuit, the secondthermal circuit, and the third thermal circuit based on the amounts ofheat which are requested by the first thermal circuit, the secondthermal circuit, and the third thermal circuit, an amount of heattransferable from the second thermal circuit to the third thermalcircuit, and an amount of heat transferable from the third thermalcircuit to the first thermal circuit; and a distribution unit configuredto distribute amounts of heat to the units which are included in thefirst thermal circuit, the second thermal circuit, and the third thermalcircuit based on the amounts of heat determined by the mediation unit.

According to the disclosure, it is possible to provide a thermal requestmediating device that can efficiently mediate thermal requests from aplurality of units in a vehicle including the plurality of unitsperforming absorption or discharge of heat.

BRIEF DESCRIPTION OF THE DRAWINGS

Features, advantages, and technical and industrial significance ofexemplary embodiments of the disclosure will be described below withreference to the accompanying drawings, in which like numerals denotelike elements, and wherein:

FIG. 1 is a functional block diagram schematically illustratingconfigurations of a thermal request mediating device and thermalcircuits according to an embodiment;

FIG. 2 is a block diagram illustrating an example of configurations ofthe thermal circuits illustrated in FIG. 1;

FIG. 3 is a diagram illustrating a hierarchical structure of functionsof the thermal request mediating device in a thermal request collectionphase;

FIG. 4 is a diagram illustrating a hierarchical structure of functionsof the thermal request mediating device in a response phase;

FIG. 5A is a flowchart illustrating a control process which is performedfor the thermal request mediating device to mediate thermal requests;

FIG. 5B is a flowchart illustrating a control process which issubsequent to FIG. 5A;

FIG. 6 is a flowchart illustrating a control process which is performedfor the thermal request mediating device to distribute amounts of heatto units in each circuit;

FIG. 7A is a diagram illustrating a first specific example of a thermalrequest mediating process;

FIG. 7B is a diagram illustrating the first specific example of thethermal request mediating process;

FIG. 7C is a diagram illustrating the first specific example of thethermal request mediating process;

FIG. 7D is a diagram illustrating the first specific example of thethermal request mediating process;

FIG. 7E is a diagram illustrating the first specific example of thethermal request mediating process;

FIG. 8 is a diagram illustrating an example of a method of calculatingamounts of heat requested by units;

FIG. 9A is a diagram illustrating a second specific example of a thermalrequest mediating process;

FIG. 9B is a diagram illustrating the second specific example of thethermal request mediating process;

FIG. 9C is a diagram illustrating the second specific example of thethermal request mediating process;

FIG. 9D is a diagram illustrating the second specific example of thethermal request mediating process;

FIG. 9E is a diagram illustrating the second specific example of thethermal request mediating process;

FIG. 10A is a diagram illustrating a third specific example of a thermalrequest mediating process;

FIG. 10B is a diagram illustrating the third specific example of thethermal request mediating process;

FIG. 10C is a diagram illustrating the third specific example of thethermal request mediating process;

FIG. 10D is a diagram illustrating the third specific example of thethermal request mediating process; and

FIG. 10E is a diagram illustrating the third specific example of thethermal request mediating process.

DETAILED DESCRIPTION OF EMBODIMENTS

A thermal request mediating device according to an embodiment of thedisclosure collects amounts of absorbed heat or amounts of dischargedheat which are requested by thermal circuits, calculates amounts ofabsorbed heat or amounts of discharged heat which are allocated to thethermal circuits, and distributes amounts of absorbed heat or amounts ofdischarged heat to units which are included in each thermal circuitbased on the calculated amounts of absorbed heat or amounts ofdischarged heat. By separately performing mediation of thermal requestsbetween thermal circuits and mediation of thermal requests in eachthermal circuit, it is possible to efficiently perform mediation ofthermal requests from a plurality of units and to reduce an influence ofa change in configuration of units of each thermal circuit.

Embodiment

Configuration

FIG. 1 is a functional block diagram schematically illustratingconfigurations of a thermal request mediating device and thermalcircuits according to an embodiment.

A thermal request mediating device 1 is a device that is mounted in avehicle including three thermal circuits such as a high-temperaturecooling circuit HT, a low-temperature cooling circuit LT, and arefrigerant circuit RE and mediates thermal requests from a plurality ofunits included in the thermal circuits. The thermal request mediatingdevice 1 can communicate with controllers of the units included in thethermal circuits via an onboard network. The high-temperature coolingcircuit HT, the low-temperature cooling circuit LT, and the refrigerantcircuit RE each include a flow passage in which a heat mediumcirculates. The units included in each thermal circuit can exchange heatwith the heat medium. The refrigerant circuit RE is coupled to thehigh-temperature cooling circuit HT and the low-temperature coolingcircuit LT such that heat exchange therewith is possible. Here, athermal request from each unit is information including a value of anamount of absorbed heat or an amount of discharged heat which isrequested by the unit. In this embodiment, an amount of absorbed heat oran amount of discharged heat is expressed by an amount of thermal energytransferred per unit time (a work ratio with a unit of W). In thefollowing description, for the purpose of convenience of explanation, anamount of absorbed heat or an amount of discharged heat which isrequested by a unit is referred to as an “amount of heat requested by aunit” and an amount of absorbed heat or an amount of discharged heatwhich is requested by a thermal circuit is referred to as an “amount ofheat requested by a thermal circuit.”

The thermal request mediating device 1 includes an acquisition unit 2, acalculation unit 3, a mediation unit 4, and a distribution unit 5. Theacquisition unit 2 acquires amounts of heat requested by controllers ofa plurality of units included in each thermal circuit by communication.The calculation unit 3 collects the amounts of heat requested by theplurality of units acquired by the acquisition unit 2 for each thermalcircuit and calculates an amount of heat requested by each thermalcircuit. The mediation unit 4 determines an allowable amount of heatallocated to each thermal circuit based on the amount of heat requestedby each thermal circuit calculated by the calculation unit 3, an amountof heat transferable between the high-temperature cooling circuit HT andthe refrigerant circuit RE, and an amount of heat transferable betweenthe low-temperature cooling circuit LT and the refrigerant circuit RE.The amount of allocated heat is an amount of absorbed heat or an amountof discharged heat which is allocated to each thermal circuit. In thisembodiment, the amount of heat transferable between thermal circuits andthe amount of heat allocated to each thermal circuit are expressed by anamount of thermal energy transferred per unit time, similarly to theamounts of requested heat. The distribution unit 5 distributes theamounts of heat to the units included in each thermal circuit based onthe amount of heat allocated to each thermal circuit determined by themediation unit 4. Details of the process which is performed by thethermal request mediating device 1 will be described later.

FIG. 2 is a block diagram illustrating an example of configurations ofthe thermal circuits illustrated in FIG. 1. In FIG. 2, flow passages inwhich a heat medium circulates are illustrated by bold lines.

The high-temperature cooling circuit HT is a circuit that circulates acoolant and includes a heater core 11, an electric heater 12, a radiator13, and a water pump 14. The high-temperature cooling circuit HT has afunction of accumulating heat in a coolant to heat a passengercompartment and a function of discharging heat received from therefrigerant circuit RE by heat exchange to the outside of the vehicle.The heater core 11 is a unit that includes a tube in which a coolantflows and a fin and performs heat exchange between the coolant and airpassing through the fin. The electric heater 12 is a unit that heats acoolant when the temperature of the coolant is insufficient. Theradiator 13 is a unit that cools a coolant with air, and includes aradiator core that includes a tube in which a coolant flows and a finand performs heat exchange between air passing through the fin and thecoolant, a grille shutter that is provided in front of the radiator coreand increases or decreases an amount of air passing through the radiatorcore, and a radiator fan that is provided behind the radiator core andforcibly blows air to the radiator core. The water pump 14 is a unitthat circulates a coolant.

In the high-temperature cooling circuit HT, the heater core 11 and theradiator 13 are units that can absorb heat from a coolant, and theelectric heater 12 is a unit that can discharge heat to the coolant. Thewater pump 14 performs neither absorption nor discharge of heat, but isa unit that can change an amount of heat discharged from the radiator 13and an amount of heat transferred to the refrigerant circuit RE via awater-cooled condenser 42 which will be described later based on a flowrate of the coolant.

The low-temperature cooling circuit LT is a circuit that circulates acoolant and includes a battery 21, a power control unit (hereinafterreferred to as a “PCU”) 22, a transaxle (hereinafter referred to as a“TA”) 23, a radiator 24, and a water pump 25. The battery 21 is a unitthat stores electric power which is supplied to a traveling motor. ThePCU 22 is a unit that includes an inverter driving the traveling motorand a DCDC converter converting a voltage and controls electric powerwhich is supplied to the traveling motor. The TA 23 is a unit in whichthe traveling motor, a power generator, a power split mechanism, and atransmission are incorporated into one body. The radiator 24 is a unitthat cools a coolant with air, and includes a radiator core thatincludes a tube in which a coolant flows and a fin and performs heatexchange between air passing through the fin and the coolant, a grilleshutter that is provided in front of the radiator core and increases ordecreases an amount of air passing through the radiator core, and aradiator fan that is provided behind the radiator core and forciblyblows air to the radiator core. The water pump 25 is a unit thatcirculates a coolant.

In the low-temperature cooling circuit LT, the radiator 24 is a unitthat can absorb heat from a coolant, and the battery 21, the PCU 22, andthe TA 23 are units that can discharge heat to the coolant via a waterjacket constituting a part of a flow passage of the coolant. The waterpump 25 performs neither absorption nor discharge of heat, but is a unitthat can control an amount of heat discharged from the battery 21, thePCU 22, and the TA 23 to the coolant, an amount of heat discharged fromthe radiator 24, and an amount of heat transferred to the refrigerantcircuit RE via a chiller 41 which will be described later based on aflow rate of the coolant. Since the low-temperature cooling circuit LTis provided to cool the battery 21, the PCU 22, and the TA 23 and tosecure reliability, the temperature of the coolant circulating in thelow-temperature cooling circuit LT is normally kept lower than thetemperature of the coolant circulating in the high-temperature coolingcircuit HT.

In the following description, for the purpose of distinction between thecoolant in the high-temperature cooling circuit HT and the coolant inthe low-temperature cooling circuit LT, the former may be referred to asa “high-temperature coolant” and the latter may be referred to as a“low-temperature coolant.”

The refrigerant circuit RE is a circuit that circulates a refrigerantwhile changing the state thereof and includes a compressor 31, anevaporator 32, and a water-cooled condenser 42. In the refrigerantcircuit RE, heat can be absorbed from air around the evaporator 32 bycondensing the refrigerant compressed by the compressor 31 using thewater-cooled condenser 42 and spraying the condensed refrigerant from anexpansion valve provided in the evaporator 32 into the evaporator 32 toexpand the refrigerant. In the refrigerant circuit RE, the compressor 31and the evaporator 32 are units that can discharge heat to therefrigerant. The water-cooled condenser 42 is a unit that can absorbheat from the refrigerant and discharge heat to the coolant in thehigh-temperature cooling circuit HT.

The refrigerant circuit RE is coupled to the low-temperature coolingcircuit LT via the chiller 41 such that heat exchange therewith ispossible, and can transfer heat generated in the low-temperature coolingcircuit LT to the refrigerant circuit RE via the chiller 41. Therefrigerant circuit RE is coupled to the high-temperature coolingcircuit HT via the water-cooled condenser 42 such that heat exchangetherewith is possible, and can transfer heat generated in therefrigerant circuit RE and/or heat transferred from the low-temperaturecooling circuit LT to the refrigerant circuit RE to the high-temperaturecooling circuit HT via the water-cooled condenser 42.

In FIG. 2, thermal circuits which are mounted in an electric vehicle areexemplified, but the thermal request mediating device according to thisembodiment can be applied to a hybrid vehicle. In a hybrid vehicle, thehigh-temperature cooling circuit HT can be used to cool an engine.

A hierarchical structure of functions of the thermal request mediatingdevice will be described below with reference to FIGS. 3 and 4.

FIG. 3 is a diagram illustrating a hierarchical structure of functionsof the thermal request mediating device in a thermal request collectionphase. FIG. 4 is a diagram illustrating a hierarchical structure offunctions of the thermal request mediating device in a response phase.

Control of thermal circuits according to this embodiment includes athermal request collection phase in which thermal requests generated inunits of the vehicle are collected and a response phase in which thecollected thermal requests are mediated and amounts of absorbed heat oramounts of discharged heat which are distributed based on the result ofmediation are returned to the units. Control which is performed in eachof the thermal request collection phase and the response phase islayered into three control layers. Processes which are performed in thecontrol layers are as follows.

Layer 1 (L1): The thermal request mediating device 1 mediates amounts ofheat requested by three thermal circuits based on the amounts of heatrequested by the thermal circuits and amounts of heat transferablebetween the thermal circuits, and determines amounts of absorbed heat oramounts of discharged heat which are allocated to the thermal circuitsand amounts of heat transferred between the thermal circuits. In Layer1, by mediating the amounts of heat requested by the thermal circuitsand the amounts of heat transferred between the thermal circuits, it ispossible to effectively use amounts of heat which are generated in thethree thermal circuits and to achieve optimization in heat utilizationefficiency in the whole vehicle and cooling efficiency of the units. Forexample, it is possible to efficiently perform use of discharged heatwhich is generated due to cooling of the units for heating the passengercompartment or promotion of cooling of the units using a plurality ofthermal circuits.

Layer 2 (L2): The thermal request mediating device 1 mediates thermalrequests of the units in each thermal circuit and distributes amounts ofheat to the units. By performing mediation of the thermal requests ineach thermal circuit in Layer 2 separately from mediation of the thermalrequests between the thermal circuits in Layer 1, it is possible toefficiently perform mediation of the thermal requests. Even whenconstituent units in each thermal circuit change due to a difference invehicle model, grade, or the like, the change in constituent units doesnot affect mediation of the thermal requests between the thermalcircuits and thus it is not necessary to change the entire mediationfunction and it is possible to improve versatility of the thermalrequest mediating device 1.

Layer 3 (L3): A controller such as an ECU that controls the unitscontrols amounts of heat absorbed from a heat medium by the units oramounts of heat discharged to the heat medium. The increase or decreaseof an amount of heat absorbed from the heat medium by a unit can beperformed, for example, by controlling a flow passage or a flow rate ofa high-temperature coolant flowing in the heater core 11, a rotationspeed of the fan or an opening level of the grill shutter of theradiator 13 or 24, or a flow rate of a coolant adjusted by the waterpump 14 or 25. The increase or decrease of an amount of heat dischargedto the heat medium by a unit can be performed, for example, bycontrolling an output of the electric heater 12, an output of thecompressor 31, an opening level of the expansion valve of the evaporator32, or power consumption from the battery 21 by the PCU 22 and the TA23. In order to efficiently control amounts of absorbed heat, amounts ofdischarged heat, and amounts of transferred heat, it is preferable tocooperatively perform control for increasing or decreasing the amountsof absorbed heat and control for increasing or decreasing the amounts ofdischarged heat in the thermal circuits.

In the example illustrated in FIGS. 3 and 4, a control layer ofdetermining situations such as the temperature of a heat medium, thetemperature inside or outside the passenger compartment, and vehiclestates such as setting of air conditioning and performing selection of athermal circuit to be used, change of a flow passage in each thermalcircuit, or the like based on the result of determination is provided asLayer 0 (L0).

The control layers in the thermal request collection phase and theresponse phase will be specifically described below in accordance withthe sequence of the mediation process.

Thermal Request Collection Phase

L3: In the thermal request collection phase illustrated in FIG. 3,first, the controllers of the units which are included in each thermalcircuit and which perform absorption of heat or discharge of heatcalculate amounts of absorbed heat or amounts of discharged heat whichare requested as control of Layer 3. The controller of each unitcalculates an amount of heat absorbed or discharged by the unit as anamount of heat absorbed or discharged per unit time which is requiredfor reaching a target control value (temperature). Since heat mediums inthe thermal circuits are different, it is difficult to collect andmediate thermal requests of the thermal circuits using only thetemperatures, but it is possible to easily perform collection of thermalrequests in Layer 2 and comparison and mediation of the thermal requestsbetween the thermal circuits in Layer 1 by unifying the units of thethermal requests.

L2: Then, as control of Layer 2, the thermal request mediating device 1acquires requested amounts of heat which are calculated in the controlof Layer 3 from the units which request absorption or discharge of heat.The thermal request mediating device 1 collects the acquired amounts ofheat requested by the thermal circuits and calculates a total requestedamount of heat of the high-temperature cooling circuit HT, a totalrequested amount of heat of the low-temperature cooling circuit LT, anda total requested amount of heat of the refrigerant circuit RE.

L1: Then, as control of Layer 1, the thermal request mediating device 1collects the requested amounts of heat of the thermal circuits which arecalculated through the control of Layer 2 and ascertains the amounts ofabsorbed heat or amounts of discharged heat which are requested by thethermal circuits.

Response Phase

L1: In the response phase illustrated in FIG. 4, first, as control ofLayer 1, the thermal request mediating device 1 mediates the amounts ofheat requested by the thermal circuits which are collected in thethermal request collection phase and allocates amounts of absorbed heator amounts of discharged heat which are allowable to the thermalcircuits. At this time, the thermal request mediating device 1 acquiresamounts of heat transferable between the thermal circuits and determinesamounts of heat which are allocated to the thermal circuits based on theacquired amounts of transferable heat. The amount of heat transferablefrom the low-temperature cooling circuit LT to the refrigerant circuitRE via the chiller 41 can be calculated based on a flow rate of alow-temperature coolant which is controlled by the water pump 25 of thelow-temperature cooling circuit LT and a temperature difference betweenthe coolant and the refrigerant. The amount of heat transferable fromthe refrigerant circuit RE to the high-temperature cooling circuit HTcan be calculated based on a control value of the compressor 31 includedin the refrigerant circuit and a temperature difference between therefrigerant and the high-temperature coolant. When the radiators 13 and24 are provided like the high-temperature cooling circuit HT and thelow-temperature cooling circuit LT illustrated in FIG. 2, the thermalrequest mediating device 1 can further acquire an amount of heatdischargeable to the outside of the vehicle from one or both of theradiators 13 and 24 and determine the amounts of absorbed heat oramounts of discharged heat which are allocated to the thermal circuitsin additional consideration of the acquired amounts of heatdischargeable.

L2: Then, as control of Layer 2, the thermal request mediating device 1distributes the amounts of absorbed heat or amounts of discharged heatto the plurality of units included in each thermal circuit based on theamounts of absorbed heat or amounts of discharged heat which areallocated to the thermal circuits in the control of Layer 1.Distribution of the amounts of absorbed heat or amounts of dischargedheat in the control of Layer 2 can be performed based on a predeterminedpriority order of the units or a predetermined distribution rule. Thethermal request mediating device 1 outputs the distributed amounts ofabsorbed heat or amounts of discharged heat to the controllers of theunits.

L3: Then, as control of Layer 3, the controllers of the units includedin each thermal circuit control the units based on the amounts ofabsorbed heat or amounts of discharged heat which are distributed by thethermal request mediating device 1.

Control Process

FIGS. 5A and 5B are flowcharts illustrating a control process which isperformed for the thermal request mediating device to mediate thermalrequests. The control process illustrated in FIGS. 5A and 5B is startedwith starting of the vehicle and is repeatedly performed at intervals ofa predetermined time.

Step S1: The acquisition unit 2 acquires amounts of heat requested bythe units included in the high-temperature cooling circuit HT, thelow-temperature cooling circuit LT, and the refrigerant circuit RE. Anamount of requested heat of each unit is an amount of absorbed heat oran amount of discharged heat which is requested by the unit and can beexpressed by a numerical value with inverted signs. When none ofabsorption and discharge of heat are requested, the amount of requestedheat is set to zero. As described above, the units of the amounts ofheat can be preferably unified into amounts of thermal energytransferred per unit time in order to easily perform collection,comparison, and mediation of the amounts of requested heat. Here, otherunits such as a temperature may be used. Thereafter, the control processprogresses to Step S2.

Step S2: The calculation unit 3 collects the amounts of requested heatof the units acquired in Step S1 by the acquisition unit 2 for eachthermal circuit and calculates a total amount of requested heat Qreq_htof the high-temperature cooling circuit HT, a total amount of requestedheat Qreq_lt of the low-temperature cooling circuit LT, and a totalamount of requested heat Qreq_re of the refrigerant circuit RE. Byexpressing the amounts of requested heat acquired in Step S1 as amountsof thermal energy transferred per unit time, it is possible to easilyperform the calculation process of Step S2 by addition and subtraction.Thereafter, the control process progresses to Step S3.

Step S3: The mediation unit 4 determines whether the amount of requestedheat Qreq_lt of the low-temperature cooling circuit LT is transferableto the refrigerant circuit RE via the chiller 41. This determination canbe performed based on a maximum amount of transferable heat of thechiller 41 which is calculated using a current temperature differencebetween the low-temperature coolant and the refrigerant or a currentflow rate in the water pump 25. The control process progresses to StepS4 when the determination result of Step S3 is YES, and the controlprocess progresses to Step S5 otherwise.

Step S4: The mediation unit 4 sets the amount of requested heat Qreq_ltas the amount of allocated heat Qcmd_lt of the low-temperature coolingcircuit LT. Thereafter, the control process progresses to Step S6.

Step S5: The mediation unit 4 sets the maximum amount of transferableheat of the chiller 41 as the amount of allocated heat Qcmd_lt to thelow-temperature cooling circuit LT. Thereafter, the control processprogresses to Step S6.

Step S6: The mediation unit 4 determines whether the sum of the amountof requested heat Qreq_lt of the low-temperature cooling circuit LT andthe amount of requested heat Qreq_re of the refrigerant circuit RE istransferable to the high-temperature cooling circuit HT via thewater-cooled condenser 42. The control process progresses to Step S7when the determination result of Step S6 is YES, and the control processprogresses to Step S8 otherwise.

Step S7: The mediation unit 4 sets the amount of requested heat Qreq_reas the amount of allocated heat Qcmd_re of the refrigerant circuit RE.Thereafter, the control process progresses to Step S13.

Step S8: The mediation unit 4 determines whether the amount of requestedheat Qreq_re of the refrigerant circuit RE is transferable to thehigh-temperature cooling circuit HT via the water-cooled condenser 42.This determination can be performed based on a maximum amount oftransferable heat of the water-cooled condenser 42 which is calculatedusing a current temperature difference between the high-temperaturecoolant and the refrigerant or a current flow rate in the water pump 14.The control process progresses to Step S9 when the determination resultof Step S8 is YES, and the control process progresses to Step S11otherwise.

Step S9: The mediation unit 4 sets the amount of requested heat Qreq_reas the amount of allocated heat Qcmd_re of the refrigerant circuit RE.Thereafter, the control process progresses to Step S10.

Step S10: The mediation unit 4 updates the amount of allocated heat

Qcmd_lt of the low-temperature cooling circuit LT to an amount of heatobtained by subtracting the amount of allocated heat Qcmd_re of therefrigerant circuit RE from the maximum amount of transferable heat ofthe water-cooled condenser 42. Thereafter, the control processprogresses to Step S13.

Step S11: The mediation unit 4 sets the maximum amount of transferableheat of the water-cooled condenser 42 as the amount of allocated heatQcmd_re of the refrigerant circuit RE. Thereafter, the control processprogresses to Step S12.

Step S12: The mediation unit 4 updates the amount of allocated heatQcmd_lt of the low-temperature cooling circuit LT to zero. Thereafter,the control process progresses to Step S13.

Step S13: The mediation unit 4 sets the sum of the amount of allocatedheat Qcmd_re of the refrigerant circuit RE and the amount of allocatedheat Qcmd_lt of the low-temperature cooling circuit LT as the amount ofallocated heat Qcmd_ht of the high-temperature cooling circuit HT.Thereafter, the control process progresses to Step S14.

Step S14: The mediation unit 4 sets the amount of allocated heat Qcmd_ltof the low-temperature cooling circuit LT as the amount of transferredheat of the chiller 41. Thereafter, the control process progresses toStep S15.

Step S15: The mediation unit 4 sets the sum of the amount of allocatedheat Qcmd_re of the refrigerant circuit RE and the amount of allocatedheat Qcmd_lt of the low-temperature cooling circuit LT as the amount oftransferred heat of the water-cooled condenser 42. Thereafter, thecontrol process ends.

Through the control process of Steps S1 to S15 described above, it ispossible to mediate the amounts of requested heat of the thermalcircuits and to allocate the amounts of absorbed heat or amounts ofdischarged heat to the thermal circuits.

In the control process, when the determination result of Step S8 is NO,that is, when it is determined that the amount of requested heat Qreq_reof the refrigerant circuit RE is not transferable to thehigh-temperature cooling circuit HT via the water-cooled condenser 42,the amount of allocated heat Qcmd_re of the refrigerant circuit RE isset to be as great as possible and the amount of allocated heat Qcmd_ltof the low-temperature cooling circuit LT is set to be zero (Steps S11and S12). Instead of this determination, the maximum amount oftransferable heat of the water-cooled condenser 42 may be distributed tothe refrigerant circuit RE and the low-temperature cooling circuit LTbased on a predetermined distribution rule.

When the radiator 24 is provided in the low-temperature cooling circuitLT as in the configuration illustrated in FIG. 2, it is preferable toconsider an amount of heat dischargeable from the radiator 24.Specifically, a step of causing the mediation unit 4 to determinewhether the requested amount of discharged heat of the low-temperaturecooling circuit LT is able to be discharged from the radiator 24 to theoutside is provided before Step S3. In this case, the amount ofrequested heat Qreq_lt of the low-temperature cooling circuit LT isdefined as an amount of heat transferred to the refrigerant circuit RE(an amount of heat which is not able to be discharged from the radiator24). When the requested amount of discharged heat of the low-temperaturecooling circuit LT can be discharged from the radiator 24 to the outsideof the vehicle, the amount of requested heat

Qreq_lt is set to zero. Otherwise, the amount of requested heat Qreq_ltcan be set to an amount of heat obtained by subtracting the amount ofheat dischargeable of the radiator 24 from the requested amount ofdischarged heat of the low-temperature cooling circuit LT.

When the radiator 13 is provided in the high-temperature cooling circuitHT as in the configuration illustrated in FIG. 2, it is preferable toconsider an amount of heat dischargeable from the radiator 13.Specifically, when the amount of transferable heat of the water-cooledcondenser 42 which is used for the determination of Step S6 is acquired,the mediation unit 4 can determine the amount of transferable heat suchthat it does not exceed the sum of the amount of absorbed heat which isrequested by the high-temperature cooling circuit HT and the amount ofheat dischargeable of the radiator 13 based on amount of absorbed heatwhich is requested by the high-temperature cooling circuit HT and theamount of heat dischargeable of the radiator 13 in addition to theamount of heat transferable from the refrigerant circuit RE to thehigh-temperature cooling circuit HT by the operation of the compressor31.

As in a third specific example which will be described later, it isconceivable that the high-temperature cooling circuit HT and therefrigerant circuit RE do not operate (do not circulate a heat medium)at the time of non-operation of air conditioning. It is conceivable thatthe refrigerant circuit RE does not operate at the time of heating. Atthe time of non-operating of the refrigerant circuit RE and/or thehigh-temperature cooling circuit HT, when the requested amount ofdischarged heat of the low-temperature cooling circuit LT cannot bedischarged using only the radiator 24 or when the temperature of thelow-temperature coolant is intended to decrease rapidly for cooling ofthe battery 21 or the like, the amounts of heat may be allocated to thethermal circuits on the assumption that the refrigerant circuit REand/or the high-temperature cooling circuit HT operates to dischargeheat from the low-temperature cooling circuit LT. Specifically, afterStep S2 in FIG. 5A, it is determined whether the requested amount ofdischarged heat by the low-temperature cooling circuit LT is greaterthan the amount of heat dischargeable of the radiator 24, and the amountof absorbed heat or the amount of discharged heat at the time ofoperation can be set to the amount of requested heat Qreq_re of therefrigerant circuit RE and/or the amount of requested heat Qreq_ht ofthe high-temperature cooling circuit HT when the amount of dischargedheat requested by the low-temperature cooling circuit LT is greater thanthe amount of heat dischargeable of the radiator 24 and the refrigerantcircuit RE and/or the high-temperature cooling circuit HT does notoperate.

FIG. 6 is a flowchart illustrating a control process which is performedfor the thermal request mediating device to distribute amounts of heatto the units in each circuit. The control process illustrated in FIG. 6is performed subsequently to the control process illustrated in FIGS. 5Aand 5B.

Step S21: The distribution unit 5 determines whether the amount ofallocated heat Qcmd_lt of the low-temperature cooling circuit LT isequal to the amount of requested heat Qreq_lt. The control processprogresses to Step S22 when the determination result of Step S21 is YES,and the control process progresses to Step S23 otherwise.

Step S22: The distribution unit 5 distributes the amounts of absorbedheat or amounts of discharged heat which are requested by the unitsincluded in the low-temperature cooling circuit LT to the units withoutany change. Thereafter, the control process progresses to Step S24.

Step S23: The distribution unit 5 distributes the amount of allocatedheat Qcmd_lt of the low-temperature cooling circuit LT to the unitsbased on a predetermined distribution rule in the low-temperaturecooling circuit LT. The distribution rule can be defined based on apriority level of cooling or heating which is set for each unit in thelow-temperature cooling circuit LT. Thereafter, the control processprogresses to Step S24.

Step S24: The distribution unit 5 determines whether the amount ofallocated heat Qcmd_re of the refrigerant circuit RE is equal to theamount of requested heat Qreq_re. The control process progresses to StepS25 when the determination result of Step S24 is YES, and the controlprocess progresses to Step S26 otherwise.

Step S25: The distribution unit 5 distributes the amounts of dischargedheat requested by the units included in the refrigerant circuit RE tothe units without any change. Thereafter, the control process progressesto Step S27.

Step S26: The distribution unit 5 distributes the amount of allocatedheat Qcmd_re of the refrigerant circuit RE to the units based on apredetermined distribution rule in the refrigerant circuit RE. Thedistribution rule can be defined based on comfortableness in thepassenger compartment. Thereafter, the control process progresses toStep S27.

Step S27: The distribution unit 5 determines whether the amount ofallocated heat Qcmd_ht of the high-temperature cooling circuit HT isequal to the amount of requested heat Qreq_ht. The control processprogresses to Step S28 when the determination result of Step S27 is YES,and the control process progresses to Step S29 otherwise.

Step S28: The distribution unit 5 distributes the amounts of absorbedheat which are requested by the units included in the high-temperaturecooling circuit HT to the units without any change. Thereafter, thecontrol process ends.

Step S29: The distribution unit 5 distributes amounts of heat to theunits based on a predetermined distribution rule in the high-temperaturecooling circuit HT such that the amount of allocated heat Qcmd_ht of thehigh-temperature cooling circuit HT is satisfied. Specifically, when theamount of allocated heat Qcmd_ht is less than the amount of absorbedheat which is requested by the high-temperature cooling circuit HT, theshortage of the amount of absorbed heat is distributed to the electricheater 12. When the amounts of discharged heat requested by thelow-temperature cooling circuit LT and the refrigerant circuit RE aregreat and the amount of allocated heat Qcmd_ht is greater than theamount of absorbed heat which is requested by the high-temperaturecooling circuit HT, the amount of absorbed heat which is distributed tothe electric heater 12 is decreased or the amount of heat dischargedfrom the radiator 13 is increased. Thereafter, the control process ends.

After the control process illustrated in FIG. 6 has ended, thecontroller of each unit included in each thermal circuit controls theunit to be controlled such that the amount of absorbed heat or theamount of discharged heat of the unit becomes the amount of heatdistributed by the distribution unit 5. Specifically, as illustrated inLayer 3 in FIG. 4, the temperature of the heater core 11, the output ofthe electric heater 12, the rotation speed of the radiator fan and/orthe opening level of the grille shutter of the radiator 13, the flowrate in the water pump 14, and the like are controlled such that theamount of absorbed heat or the amount of discharged heat of each unitbecomes the amount of heat which is distributed in the high-temperaturecooling circuit HT. In the low-temperature cooling circuit LT, the powerconsumption of the battery 21, the output of the PCU 22, the output ofthe TA 23, the rotation speed of the radiator fan and/or the openinglevel of the grille shutter of the radiator 24, the flow rate of thecoolant which is adjusted by the water pump 25, and the like arecontrolled such that the amount of absorbed heat or the amount ofdischarged heat of each unit becomes the amount of heat which isdistributed. In the refrigerant circuit RE, the output of the compressor31, the opening level of the expansion valve for spraying therefrigerant into the evaporator 32, and the like are controlled suchthat the amount of absorbed heat or the amount of discharged heat ofeach unit becomes the amount of heat which is distributed.

FIRST SPECIFIC EXAMPLE

FIGS. 7A to 7E are diagrams illustrating a first specific example of athermal request mediating process. FIG. 8 is a diagram illustrating anexample of a method of calculating amounts of heat requested by theunits. In the first specific example, it is assumed that a heatabsorption request is issued from the high-temperature cooling circuitHT and heat discharge requests are issued from the low-temperaturecooling circuit LT and the refrigerant circuit RE. In FIGS. 7A to 7E,the positive direction of the vertical axis represents an amount ofabsorbed heat of a unit from a heat medium, and the negative directionof the vertical axis represents an amount of heat discharged to the heatmedium. An amount of heat transferred from the low-temperature coolingcircuit LT to the refrigerant circuit RE is set as the amount ofdischarged heat of the chiller 41, and an amount of heat transferredfrom the refrigerant circuit RE to the high-temperature cooling circuitHT is set as the amount of discharged heat of the water-cooled condenser42. The method of expressing the amount of absorbed heat and the amountof discharged heat in the drawings is true of FIGS. 9A to 10E which willbe described later.

First, as illustrated in FIG. 7A, the acquisition unit 2 acquiresamounts of heat requested by the units included in each thermal circuit(L3 of the thermal request collection phase). The controller of eachunit stores map data in which temporal changes of an amount of absorbedheat or an amount of discharged heat required for changing thetemperature of the control object (such as an air temperature or acoolant temperature) from a current value to a target control value aremapped in advance as illustrated in FIG. 8, and acquires the necessaryamount of absorbed heat or the necessary amount of discharged heat basedon the map data. The requested amounts of heat of the heater core 11,the evaporator 32, the compressor 31, the battery 21, the PCU 22, andthe TA 23 are referred to as Qreq_htr, Qreq_eva, Qreq_cp, Qreq_bat,Qreq_pcu, and Qreq_ta, respectively.

Then, as illustrated in FIG. 7B, the calculation unit 3 collects theamounts of heat requested by the thermal circuits and calculates therequested amount of heat Qreq_ht of the high-temperature cooling circuitHT, the requested amount of heat Qreq_re of the refrigerant circuit RE,and the requested amount of heat Qreq_lt of the low-temperature coolingcircuit LT through the following calculation (L2 of the thermal requestcollection phase). Through the collection process in the calculationunit 3, the mediation unit 4 can refer to the requested amounts of heatof the thermal circuits (L1 of the thermal request collection phase).Qreq_ht=Qreq_htrQreq_re=Qreq_eva+Qreq_cpQreq_lt=Qreq_bat+Qreq_pcu+Qreq_ta

Then, as illustrated in FIG. 7C, the mediation unit 4 mediates therequested amounts of heat based on the requested amounts of heat of thehigh-temperature cooling circuit HT, the refrigerant circuit RE, and thelow-temperature cooling circuit LT which are calculated by thecalculation unit 3, the maximum amount of transferable heat of thechiller 41, and the maximum amount of transferable heat of thewater-cooled condenser 42 (L1 of the response phase). In the exampleillustrated in FIG. 7C, the requested amount of heat of thelow-temperature cooling circuit LT is equal to or less than the maximumamount of transferable heat of the chiller 41, and the sum of therequested amounts of heat of the refrigerant circuit RE and thelow-temperature cooling circuit LT is equal to or less than the maximumamount of transferable heat of the water-cooled condenser 42 and lessthan the requested amount of heat of the high-temperature coolingcircuit HT

Then, as illustrated in FIG. 7D, the mediation unit 4 allocates anamount of absorbed heat or an amount of discharged heat to each thermalcircuit (L2 of the response phase). As illustrated in FIG. 7C, sinceheat which is discharged from the refrigerant circuit RE and thelow-temperature cooling circuit LT is all transferable to thehigh-temperature cooling circuit HT, the mediation unit 4 sets theamount of allocated heat Qcmd_re of the refrigerant circuit RE and theamount of allocated heat Qcmd_lt of the low-temperature cooling circuitLT to the requested amounts of heat Qreq_re and Qreq_lt. The mediationunit 4 sets the amount of allocated heat Qcmd_ht of the high-temperaturecooling circuit HT to the sum of the requested amounts of heat Qreq_reand Qreq_lt.

Then, as illustrated in FIG. 7E, the distribution unit 5 distributes theamounts of absorbed heat or amounts of discharged heat which areallocated to the thermal circuits to the units in each thermal circuit(L3 of the response phase). In this example, the distribution unit 5distributes Qreq_eva, Qreq_cp, Qreq_bat, Qreq_pcu, and Qreq_ta to theevaporator 32, the compressor 31, the battery 21, the PCU 22, and the TA23, respectively. Since the amount of allocated heat Qcmd_lt of therefrigerant circuit RE and the low-temperature cooling circuit LT is thesame as the requested amount of heat, the amounts of absorbed heat oramounts of discharged heat which are distributed to the units are thesame as the amounts of absorbed heat or amounts of discharged heat whichare requested by the units. As an amount of transferred heat, Qcmd_chilwhich is equal to the amount of discharged heat which is requested bythe low-temperature cooling circuit LT is distributed to the chiller 41.As an amount of transferred heat, Qcmd_wcon which is equal to the sum ofthe requested amounts of discharged heat of the refrigerant circuit REand the low-temperature cooling circuit LT is distributed to thewater-cooled condenser 42. As illustrated in FIG. 7C, since the sum ofthe requested amounts of discharged heat of the refrigerant circuit REand the low-temperature cooling circuit LT is less than the amount ofabsorbed heat which is requested by the high-temperature cooling circuitHT, all the amounts of discharged heat of the low-temperature coolingcircuit LT and the refrigerant circuit RE are transferred to thehigh-temperature cooling circuit HT via the chiller 41 and thewater-cooled condenser 42, and the amount of absorbed heat which is ashortage is distributed to the electric heater 12 for replenishment inorder to secure the requested amount of heat of the high-temperaturecooling circuit HT.

SECOND SPECIFIC EXAMPLE

FIGS. 9A to 9E are diagrams illustrating a second specific example ofthe thermal request mediating process. In the second specific example,it is assumed that the units of the low-temperature cooling circuit LTare cooled using the refrigerant circuit RE at the time of cooling. Inthis example, it is assumed that cooling of the battery 21 using onlythe radiator 24 of the low-temperature cooling circuit LT is notsufficient and the amount of discharged heat of the low-temperaturecooling circuit LT needs to be discharged to the outside of the vehiclevia the refrigerant circuit RE.

First, as illustrated in FIG. 9A, the acquisition unit 2 acquiresamounts of heat requested by the units included in each thermal circuit.The requested amounts of heat of the radiator 13, the evaporator 32, thecompressor 31, the battery 21, the TA 23, and the PCU 23 are referred toas Qreq_htrad, Qreq_eva, Qreq_cp, Qreq_bat, Qreq_ta, and Qreq_pcu,respectively.

Then, as illustrated in FIG. 9B, the calculation unit 3 collects therequested amounts of heat for each thermal circuit and calculates therequested amount of heat Qreq_ht of the high-temperature cooling circuitHT, the requested amount of heat Qreq_re of the refrigerant circuit RE,and the requested amount of heat Qreq_lt of the low-temperature coolingcircuit LT through the following calculation.Qreq_ht=Qreq_htradQreq_re=Qreq_eva+Qreq_cpQreq_lt=Qreq_bat+Qreq_ta+Qreq_pcu

Then, as illustrated in FIG. 9C, the mediation unit 4 mediates therequested amounts of heat based on the requested amounts of heat of thehigh-temperature cooling circuit HT, the refrigerant circuit RE, and thelow-temperature cooling circuit LT which are calculated by thecalculation unit 3, the maximum amount of transferable heat of thechiller 41, and the maximum amount of transferable heat of thewater-cooled condenser 42. In the example illustrated in FIG. 9C, therequested amount of heat of the low-temperature cooling circuit LT isequal to or less than the maximum amount of transferable heat of thechiller 41, and the sum of the requested amounts of heat of therefrigerant circuit RE and the low-temperature cooling circuit LT isgreater than the maximum amount of transferable heat of the water-cooledcondenser 42.

Therefore, as illustrated in FIG. 9D, the mediation unit 4 sets theamount of allocated heat Qcmd_re of the refrigerant circuit RE to thesame amount of heat as the requested amount of heat Qreq_re and sets theamount of allocated heat Qcmd_lt of the low-temperature cooling circuitLT to a value obtained by subtracting the amount of allocated heatQcmd_re of the refrigerant circuit RE from the maximum amount oftransferable heat of the water-cooled condenser 42. In this example, themediation unit 4 preferentially allocates an amount of discharged heatto the refrigerant circuit RE and allocates an amount of discharged heatless than the requested amount of discharged heat to the low-temperaturecooling circuit LT. The mediation unit 4 sets the amount of allocatedheat Qcmd_ht of the high-temperature cooling circuit HT to the sum ofthe requested amount of heat of the high-temperature cooling circuit HTand the allocated amounts of heat of the refrigerant circuit RE and thelow-temperature cooling circuit LT.

Then, as illustrated in FIG. 9E, the distribution unit 5 distributes anamount of absorbed heat or an amount of discharged heat to the units ofeach thermal circuit. In this example, since the amount of allocatedheat of the refrigerant circuit RE is the same as the requested amountof heat, the distribution unit 5 distributes Qcmd_eva and Qcmd_cp whichthe same as the requested amounts of discharged heat to the evaporator32 and the compressor 31. Since the amount of allocated heat Qcmd_lt ofthe low-temperature cooling circuit LT is less than the requested amountof discharged heat, the distribution unit 5 distributes the amount ofallocated heat Qcmd_lt to the units based on a predetermined priority.In the example illustrated in FIG. 9E, priority is given to curbing ofdeterioration of the battery 21 and Qcmd_bat which is distributed to thebattery 21 is decreased less than the requested amount of dischargedheat. In this case, for example, by limiting supply of electric powerfrom the battery 21 to the PCU 22, radiation of heat from the battery 21(the amount of discharged heat) is curbed. Qcmd_chil which is equal tothe amount of allocated heat of the low-temperature cooling circuit LTis distributed as an amount of transferred heat to the chiller 41.Qcmd_wcon which is equal to the sum of the amounts of allocated heat ofthe refrigerant circuit RE and the low-temperature cooling circuit LT isdistributed as an amount of transferred heat to the water-cooledcondenser 42. The sum of the requested amount of heat Qreq_htradacquired in FIG. 9B and the amounts of allocated heat of the refrigerantcircuit RE and the low-temperature cooling circuit LT is distributed asan amount of discharged heat to the radiator 13 of the high-temperaturecooling circuit HT. Third specific example

FIGS. 10A to 10E are diagrams illustrating a third specific example ofthe thermal request mediating process. In the third specific example, itis assumed that the battery 21 of the low-temperature cooling circuit LTis cooled at the time of non-operation of air conditioning. In thisexample, it is assumed that cooling of the battery 21 using only theradiator 24 of the low-temperature cooling circuit LT is not sufficientand the amount of discharged heat of the low-temperature cooling circuitLT needs to be discharged to the outside of the vehicle via therefrigerant circuit RE.

First, as illustrated in FIG. 10A, the acquisition unit 2 acquiresamounts of heat requested by the units included in each thermal circuit.In this example, since air conditioning is not used, the requestedamounts of heat of the units included in the high-temperature coolingcircuit HT and the refrigerant circuit RE are zero and only cooling ofthe battery 21 is requested. The requested amount of heat of the battery21 is defined as Qreq_bat.

Then, as illustrated in FIG. 10B, the calculation unit 3 collects therequested amounts of heat for each thermal circuit. Since only dischargeof heat from the battery 21 is requested, the requested amount of heatQreq_ht of the high-temperature cooling circuit HT, the requested amountof heat Qreq_re of the refrigerant circuit RE, and the requested amountof heat Qreq_lt of the low-temperature cooling circuit LT are asfollows.Qreq_ht=Qreq_re=0Qreq_lt=Qreq_bat

Then, the mediation unit 4 mediates the requested amounts of heat basedon the requested amounts of heat of the high-temperature cooling circuitHT, the refrigerant circuit RE, and the low-temperature cooling circuitLT which are calculated by the calculation unit 3, the maximum amount oftransferable heat of the chiller 41, and the maximum amount oftransferable heat of the water-cooled condenser 42. Since airconditioning is not used in this step, the compressor 31 of therefrigerant circuit RE needs to operate to perform discharge of heatfrom the low-temperature cooling circuit LT. Therefore, as illustratedin FIG. 10C, the mediation unit 4 presumes that the requested amount ofheat Qreq_re is generated with the operation of the compressor 31 of therefrigerant circuit RE, and performs a mediation process. In thefollowing description, for the purpose of convenience of explanation,the requested amount of heat of the refrigerant circuit RE which is setherein is referred to as a “presumptive requested amount of heat.” Inthe example illustrated in FIG. 10C, the requested amount of heat of thelow-temperature cooling circuit LT is equal to or less than the maximumamount of transferable heat of the chiller 41, and the sum of therequested amount of heat of the refrigerant circuit RE and thepresumptive requested amount of heat Qreq_re of the low-temperaturecooling circuit LT is equal to or less than the maximum amount oftransferable heat of the water-cooled condenser 42.

Therefore, as illustrated in FIG. 10D, the mediation unit 4 sets theamount of allocated heat Qcmd_re of the refrigerant circuit RE to thesame amount of heat as the presumptive requested amount of heat Qreq_reand sets the amount of allocated heat Qcmd_lt of the low-temperaturecooling circuit LT to the same amount of heat as the requested amount ofheat Qreq_lt. The mediation unit 4 sets the amount of allocated heatQcmd_ht of the high-temperature cooling circuit HT to the sum of theamounts of allocated heat of the refrigerant circuit RE and thelow-temperature cooling circuit LT.

Then, as illustrated in FIG. 10E, the distribution unit 5 distributesthe amounts of allocated heat to the units of each thermal circuit. Inthis example, the distribution unit 5 distributes Qcmd_cp which is equalto the amount of allocated heat Qcmd_re of the refrigerant circuit RE tothe compressor 31 for circulating the refrigerant. The distribution unit5 distributes Qcmd_bat which is equal to the amount of allocated heatQcmd_lt of the low-temperature cooling circuit LT to the battery 21. Thedistribution unit 5 distributes Qcmd_chil which is equal to the amountof allocated heat of the low-temperature cooling circuit LT as an amountof transferred heat to the chiller 41. The distribution unit 5distributes Qcmd_wcon which is equal to the sum of the amounts ofallocated heat of the refrigerant circuit RE and the low-temperaturecooling circuit LT as an amount of transferred heat to the water-cooledcondenser 42. The sum of the amounts of allocated heat of therefrigerant circuit RE and the low-temperature cooling circuit LT isdistributed as an amount of discharged heat to the radiator 13 of thehigh-temperature cooling circuit HT.

The thermal request mediating device 1 can be realized by causing acomputer such as an ECU including a processor, a ROM, and/or a RAM toperform the control process illustrated in FIGS. 5A to 6.

Advantages or the Like

As described above, in the thermal request mediating device 1 accordingto this embodiment, control for thermal requests of a plurality of unitsis layered, and distribution of an amount of heat in each thermalcircuit and mediation of the requested amounts of heat between thethermal circuits (adjustment of the amounts of heat requested by thethermal circuits) are performed in different control layers.Accordingly, the thermal requests of the units do not need to beindividually considered at the time of mediation of the requestedamounts of heat between the thermal circuits, and the requested amountsof heat between the thermal circuits do not need to be considered at thetime of distribution of the amount of heat in each thermal circuit.Accordingly, it is possible to efficiently perform mediation of thethermal requests from a plurality of units mounted in the vehicle anddistribution of the amounts of heat to the units. Since the individualthermal requests form the units are not directly referred to at the timeof mediation of the requested amounts of heat between the thermalcircuits, the thermal request mediating device 1 according to thisembodiment can be applied to a case in which the constituent units ofthe thermal circuits vary depending on a vehicle model, a grade, aconfiguration of a power train, or the like, and excellent versatilitycan be achieved.

By unifying an amount of absorbed heat, an amount of discharged heat, anamount of transferable heat, an amount of transferred heat, and anamount of heat dischargeable which are used for the thermal requestmediating device 1 to perform a control process into an amount ofthermal energy transferred per unit time, it is possible to easilyperform collection, mediation, and distribution of the thermal requests.

When the high-temperature cooling circuit HT includes the radiator 13,it is possible to promote discharge of heat from other thermal circuitsor to accurately calculate an amount of heat dischargeable from otherthermal circuits by further taking consideration of the amount of heatdischargeable of the radiator 13 at the time of mediation of therequested amounts of heat between the thermal circuits.

When the low-temperature cooling circuit LT includes the radiator 23, itis possible to preferentially perform cooling of the units included inthe low-temperature cooling circuit LT by further taking considerationof the amount of heat dischargeable of the radiator 24 at the time ofmediation of the requested amounts of heat between the thermal circuits.

OTHER MODIFIED EXAMPLES

In the above-mentioned embodiment, the amounts of absorbed heat or theamounts of discharged heat of the units and the thermal circuits areexpressed by amounts of thermal energy transferred per unit time (inunits of W), but the amounts of absorbed heat or the amounts ofdischarged heat of the units and the thermal circuits may be expressedby amounts of thermal energy (in units of J) required for apredetermined control time. In this case, an amount of heat transferablebetween thermal circuits is expressed by an amount of thermal energytransferred per unit time similarly to the requested amounts of heat.When the amounts of absorbed heat or the amounts of discharged heat ofthe units are expressed by amounts of thermal energy, it is possible toeasily perform collection, mediation, and distribution of requestedamounts of heat through the control processes which have been describedabove with reference to FIGS. 5A to 6 and to reduce an influence of achange of the units of each thermal circuit.

The disclosure can be embodied as a thermal request mediating devicethat mediates a plurality of thermal requests which is issued in avehicle.

What is claimed is:
 1. A thermal request mediating device that ismounted in a vehicle including a first thermal circuit configured tocirculate a high-temperature coolant, a second thermal circuitconfigured to circulate a low-temperature coolant, a third thermalcircuit configured to circulate a refrigerant while changing a state ofthe refrigerant and to exchange heat with the first thermal circuit andthe second thermal circuit, and a plurality of units configured toperform absorption or discharge of heat via any one of heat mediumswhich circulate in the first thermal circuit, the second thermalcircuit, and the third thermal circuit, the thermal request mediatingdevice comprising: an acquisition unit configured to acquire amounts ofheat which are requested by the plurality of units, the amounts of heatbeing amounts of absorbed heat or amounts of discharged heat; acalculation unit configured to calculate amounts of heat which arerequested by the first thermal circuit, the second thermal circuit, andthe third thermal circuit based on the amounts of heat which arerequested by the plurality of units and which are acquired by theacquisition unit; a mediation unit configured to determine amounts ofheat which are allocated to the first thermal circuit, the secondthermal circuit, and the third thermal circuit based on the amounts ofheat which are requested by the first thermal circuit, the secondthermal circuit, and the third thermal circuit, an amount of heattransferable from the second thermal circuit to the third thermalcircuit, and an amount of heat transferable from the third thermalcircuit to the first thermal circuit; and a distribution unit configuredto distribute amounts of heat to the units which are included in thefirst thermal circuit, the second thermal circuit, and the third thermalcircuit based on the amounts of heat determined by the mediation unit.2. The thermal request mediating device according to claim 1, whereinthe amounts of absorbed heat, the amounts of discharged heat, and theamounts of transferable heat are expressed by amounts of thermal energytransferred per unit time.
 3. The thermal request mediating deviceaccording to claim 1, wherein the first thermal circuit includes a firstradiator that cools the coolant, and the mediation unit is configured todetermine the amounts of heat which are allocated to the first thermalcircuit, the second thermal circuit, and the third thermal circuitfurther based on an amount of heat dischargeable from the firstradiator.
 4. The thermal request mediating device according to claim 1,wherein the second thermal circuit includes a second radiator that coolsthe coolant, and the mediation unit is configured to determine amountsof heat which are allocated to the first thermal circuit, the secondthermal circuit, and the third thermal circuit further based on anamount of heat dischargeable from the second radiator.
 5. The thermalrequest mediating device according to claim 1, wherein the secondthermal circuit and the third thermal circuit are coupled to each othervia a first heat exchanger, and the mediation unit is configured todetermine an amount of discharged heat which is allocated to the secondthermal circuit as an amount of transferred heat that is transferredfrom the second thermal circuit to the third thermal circuit via thefirst heat exchanger.
 6. The thermal request mediating device accordingto claim 1, wherein the first thermal circuit and the third thermalcircuit are coupled to each other via a second heat exchanger, and themediation unit is configured to determine a sum of the amounts ofdischarged heat which are allocated to the second thermal circuit andthe third thermal circuit as an amount of transferred heat that istransferred from the third thermal circuit to the first thermal circuitvia the second heat exchanger.
 7. The thermal request mediating deviceaccording to claim 1, wherein the mediation unit is configured todetermine an amount of transferred heat that is transferred from thesecond thermal circuit to the third thermal circuit and an amount oftransferred heat that is transferred from the third thermal circuit tothe first thermal circuit based on the amounts of heat which areallocated to the first thermal circuit, the second thermal circuit, andthe third thermal circuit.
 8. The thermal request mediating deviceaccording to claim 1, wherein the distribution unit is configured todistribute the amounts of heat for the plurality of units included inthe first thermal circuit based on whether the amount of heat which isallocated to the first thermal circuit matches the amount of heatrequested by the first thermal circuit, distribute the amounts of heatfor the plurality of units included in the second thermal circuit basedon whether the amount of heat which is allocated to the second thermalcircuit matches the amount of heat requested by the first thermalcircuit, and distribute the amounts of heat for the plurality of unitsincluded in the third thermal circuit based on whether the amount ofheat which is allocated to the third thermal circuit matches the amountof heat requested by the first thermal circuit.
 9. The thermal requestmediating device according to claim 8, wherein the distribution unit isconfigured to distribute the amounts of heat for the plurality of unitsincluded in the first thermal circuit based on a predetermineddistribution rule when the amount of heat which is allocated the firstthermal circuit does not match the amount of heat which is required bythe first thermal circuit, distribute the amounts of heat for theplurality of units included in the second thermal circuit based on thepredetermined distribution rule when the amount of heat which isallocated the second thermal circuit does not match the amount of heatwhich is required by the second thermal circuit, and distribute theamounts of heat for the plurality of units included in the third thermalcircuit based on the predetermined distribution rule when the amount ofheat which is allocated the third thermal circuit does not match theamount of heat which is required by the third thermal circuit.
 10. Thethermal request mediating device according to claim 9, wherein thepredetermined distribution rule is based on at least one ofcomfortableness in a passenger compartment or priority levels of coolingor heating which are set for the plurality of units.
 11. The thermalrequest mediating device according to claim 8, wherein the distributionunit is configured to distribute the amounts of heat for the pluralityof units included in the first thermal circuit based on the amounts ofheat which are required by the plurality of units included in the firstthermal circuit when the amount of heat which is allocated the firstthermal circuit matches the amount of heat which is required by thefirst thermal circuit, distribute the amounts of heat for the pluralityof units included in the second thermal circuit based on the amounts ofheat which are required by the plurality of units included in the secondthermal circuit when the amount of heat which is allocated the secondthermal circuit matches the amount of heat which is required by thesecond thermal circuit, and distribute the amounts of heat for theplurality of units included in the third thermal circuit based on theamounts of heat which are required by the plurality of units included inthe third thermal circuit when the amount of heat which is allocated thethird thermal circuit matches the amount of heat which is required bythe third thermal circuit.